m68k: fix compiler warning by properly inlining flat_set_persistent()

This patch removes the following warning:
fs/binfmt_flat.c:752: warning: unused variable 'persistent'.
There is neither functionality change, nor extra code generated.
Signed-off-by: NEzequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: NGreg Ungerer <gerg@uclinux.org>

arch/m68k/include/asm/flat.h

@@ -11,6 +11,11 @@
 #define	flat_get_addr_from_rp(rp, relval, flags, p)	get_unaligned(rp)
 #define	flat_put_addr_at_rp(rp, val, relval)	put_unaligned(val,rp)
 #define	flat_get_relocate_addr(rel)		(rel)
-#define	flat_set_persistent(relval, p)		0
+
+static inline int flat_set_persistent(unsigned long relval,
+				      unsigned long *persistent)
+{
+	return 0;
+}
 
 #endif /* __M68KNOMMU_FLAT_H__ */