f2fs: make is_multimedia_file code align with its name

The code conditions put inside the function is_multimedia_file are
reverse to the name i.e, we need to negate the return to actually
check if the file is a multimedia file. So, change the code and usage
path to align both the name and comparision conditions.

Signed-off-by: Namjae Jeon <[e-mail]>
Signed-off-by: Amit Sahrawat <[e-mail]>
Signed-off-by: Jaegeuk Kim <[e-mail]>

fs/f2fs/namei.c

···
 	int ret;
 
 	if (sublen > slen)
-		return 1;
+		return 0;
 
 	ret = memcmp(s + slen - sublen, sub, sublen);
 	if (ret) {	/* compare upper case */
···
 		char upper_sub[8];
 		for (i = 0; i < sublen && i < sizeof(upper_sub); i++)
 			upper_sub[i] = toupper(sub[i]);
-		return memcmp(s + slen - sublen, upper_sub, sublen);
+		return !memcmp(s + slen - sublen, upper_sub, sublen);
 	}
 
-	return ret;
+	return !ret;
 }
 
 /*
···
 
 	int count = le32_to_cpu(sbi->raw_super->extension_count);
 	for (i = 0; i < count; i++) {
-		if (!is_multimedia_file(name, extlist[i])) {
+		if (is_multimedia_file(name, extlist[i])) {
 			set_cold_file(inode);
 			break;
 		}