Newer versions of clang optimize the calls to use unlocked variants of
these functions
Fixes
| capabilities.c:(.text+0xb4): undefined reference to `fread_unlocked'
| arm-yoe-linux-gnueabi-ld.bfd: capabilities.c:(.text+0x11a): undefined
reference to `fwrite_unlocked'
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Cc: Andrea Adami <andrea.adami@gmail.com>