kmod_config: fix kcmd line parser with dots after =

Check if '=' appeared before the dot. In this case, it's not a valid
module option in kernel command line.

The command line that was failing is:

"root=/dev/sda3 ro pcie_aspm=force init=/sbin/bootchartd
	initrd=../initramfs-linux.img BOOT_IMAGE=../vmlinuz-linux"

libkmod/libkmod-config.c

@@ -460,7 +460,8 @@ static int kmod_config_parse_kcmdline(struct kmod_config *config)
 			param = p + 1;
 			break;
 		case '=':
-			value = p + 1;
+			if (param != NULL)
+				value = p + 1;
 			break;
 		}
 	}