Recheck the root filesystem after expanding it.

Checking the root filesystem before mounting it is always a good idea.
But after changing the root filesystem, it is especially important to
(re-)check it to ensure everything went fine. So add that check.

rootfs/etc/initramfs-tools/scripts/local-bottom/rpi-resizerootfs

@@ -45,6 +45,9 @@ wait_for_udev 5
 partprobe "$rootdev"
 resize2fs "$rootpart"
 
+# After resizing, (re)check the root partition's filesystem
+fsck "$rootpart"
+
 # Remount root
 # Don't quote ${ROOTFLAGS} as that results in an extra (empty) argument
 # to 'mount', which in turn causes a boot failure