scsi: megaraid: Fix error check return value of register_chrdev()

If major equals 0, register_chrdev() returns an error code when it fails.
This function dynamically allocates a major and returns its number on
success, so we should use "< 0" to check it instead of "!".

Link: https://lore.kernel.org/r/20220418105755.2558828-1-lv.ruyi@zte.com.cn
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid.c

@@ -4607,7 +4607,7 @@ static int __init megaraid_init(void)
 	 * major number allocation.
 	 */
 	major = register_chrdev(0, "megadev_legacy", &megadev_fops);
-	if (!major) {
+	if (major < 0) {
 		printk(KERN_WARNING
 				"megaraid: failed to register char device\n");
 	}