CryptoPkg/IntrinsicLib: Fix the warning on memset

CryptoPkg/IntrinsicLib: Fix the warning on memset

Gcc issued the warning when compiling CryptoPkg:

CryptoPkg/Library/Include/CrtLibSupport.h:135:17: warning: type of 'memset' does not match original declaration [-Wlto-type-mismatch]
 void           *memset     (void *, int, size_t);
                 ^
CryptoPkg/Library/IntrinsicLib/MemoryIntrinsics.c:27:8: note: type mismatch in parameter 2
 void * memset (void *dest, char ch, size_t count)
        ^

This commit changes the type of ch from char to int to match the
declaration.

Cc: Qin Long <qin.long@intel.com>
Cc: Ting Ye <ting.ye@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Qin Long <qin.long@intel.com>