utils: Allocate enough space or page_no in do_pagination()
utils: Allocate enough space or page_no in do_pagination()

Compiling with GCC 9.1.0 produced the following warnings about
do_pagination()

  CC    utils.o
utils.c: In function ‘do_pagination’:
utils.c:906:40: warning: ‘%d’ directive output may be truncated writing
between 1 and 11 bytes into a region of size 10 [-Wformat-truncation=]
  906 |    snprintf(page_no, sizeof(page_no), "%d", rqpage - 1);
      |                                        ^~
utils.c:906:39: note: directive argument in the range [-2147483648,
2147483646]
  906 |    snprintf(page_no, sizeof(page_no), "%d", rqpage - 1);
      |                                       ^~~~
In file included from /usr/include/stdio.h:937,
                 from utils.c:15:
/usr/include/bits/stdio2.h:64:10: note: ‘__builtin___snprintf_chk’
output between 2 and 12 bytes into a destination of size 10
   64 |   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL
- 1,
      |
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   65 |        __bos (__s), __fmt, __va_arg_pack ());
      |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
utils.c:903:42: warning: ‘__builtin___snprintf_chk’ output may be
truncated before the last format character [-Wformat-truncation=]
  903 |    snprintf(page_no, sizeof(page_no), "%d", nr_pages);
      |                                          ^
In file included from /usr/include/stdio.h:937,
                 from utils.c:15:
/usr/include/bits/stdio2.h:64:10: note: ‘__builtin___snprintf_chk’
output between 2 and 11 bytes into a destination of size 10
   64 |   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL
- 1,
      |
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   65 |        __bos (__s), __fmt, __va_arg_pack ());
      |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
utils.c:913:40: warning: ‘%d’ directive output may be truncated writing
between 1 and 11 bytes into a region of size 10 [-Wformat-truncation=]
  913 |    snprintf(page_no, sizeof(page_no), "%d", rqpage + 1);
      |                                        ^~
utils.c:913:39: note: directive argument in the range [-2147483647,
2147483647]
  913 |    snprintf(page_no, sizeof(page_no), "%d", rqpage + 1);
      |                                       ^~~~
In file included from /usr/include/stdio.h:937,
                 from utils.c:15:
/usr/include/bits/stdio2.h:64:10: note: ‘__builtin___snprintf_chk’
output between 2 and 12 bytes into a destination of size 10
   64 |   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL
- 1,
      |
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   65 |        __bos (__s), __fmt, __va_arg_pack ());
      |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Due to using ints for storing the page numbers, when converting with to
strings we need allocate 12 bytes for them -2147483648..2147483646 + the
terminating NUL byte.

Yes, they can't be -ve (I think), but this is the simplest fix..

Signed-off-by: Andrew Clayton <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@digital-domain.net>

ac000/fcgi_app_core,ac000/fcgi_app_core