device/oprom/x86emu/sys.c: Use __func__

Change-Id: Ia278e1f2d1162fa9541bf0cead3b2734144190be
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49543
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/device/oprom/x86emu/sys.c

@@ -64,7 +64,7 @@ static u8 *mem_ptr(u32 addr, int size)
 	u8 *retaddr = 0;
 
 	if (addr > M.mem_size - size) {
-		DB(printf("mem_ptr: address %#x out of range!\n", addr);)
+		DB(printf("%s: address %#x out of range!\n", __func__, addr);)
 		    HALT_SYS();
 	}
 	if (addr < 0x200) {