staging: r8188eu: get a string from the user correctly
staging: r8188eu: get a string from the user correctly

The original code had two bugs:
1) It didn't check if the string was zero length so it could oops when
   it tried to dereference the ZERO_SIZE_PTR.
2) It didn't enforce that the string was NUL terminated.

It was also messy as pants.

Signed-off-by: Dan Carpenter <ff341aa343d564f9e53e9dcb6996be8c04859a66@oracle.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

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