MIPS: Fix strnlen_user() return value in case of overlong strings.
MIPS: Fix strnlen_user() return value in case of overlong strings.

We were returning maxlen like the userland strnlen if no '\0' character
was encountered while the kernel version is expected to return a value
larger than maxlen.  Fixed to return maxlen + 1.

Signed-off-by: Ralf Baechle <92f48d309cda194c8eda36aa8f9ae28c488fa208@linux-mips.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs