Allow mounting squashfs partitions

Change-Id: Ifb8f84063a406db7aad3f9ef12c349ea09a54e07
Signed-off-by: Mohamad Ayyash <mkayyash@google.com>

(cherry picked from commit 0ddfa329ac)

roots.cpp

@@ -111,6 +111,7 @@ int ensure_path_mounted(const char* path) {
         }
         return mtd_mount_partition(partition, v->mount_point, v->fs_type, 0);
     } else if (strcmp(v->fs_type, "ext4") == 0 ||
+               strcmp(v->fs_type, "squashfs") == 0 ||
                strcmp(v->fs_type, "vfat") == 0) {
         result = mount(v->blk_device, v->mount_point, v->fs_type,
                        v->flags, v->fs_options);