syscalls: Fix offset type of ksys_ftruncate()

After the commit below, truncate() on x86 32bit uses ksys_ftruncate(). But
ksys_ftruncate() truncates the offset to unsigned long.

Switch the type of offset to loff_t which is what do_sys_ftruncate()
expects.

Fixes: 121b32a (x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments)
Signed-off-by: Jiri Slaby <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Brian Gerst <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

Author: Jiri Slaby

include/linux/syscalls.h

@@ -1360,7 +1360,7 @@ static inline long ksys_lchown(const char __user *filename, uid_t user,
 
 extern long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
 
-static inline long ksys_ftruncate(unsigned int fd, unsigned long length)
+static inline long ksys_ftruncate(unsigned int fd, loff_t length)
 {
 	return do_sys_ftruncate(fd, length, 1);
 }