block: qemu-iotests, add quotes to $TEST_IMG usage io pattern tests

The usage of $TEST_IMG was not properly quoted everywhere in
common.pattern.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

tests/qemu-iotests/common.pattern

@@ -28,7 +28,7 @@ function do_is_allocated() {
 }
 
 function is_allocated() {
-    do_is_allocated "$@" | $QEMU_IO $TEST_IMG | _filter_qemu_io
+    do_is_allocated "$@" | $QEMU_IO "$TEST_IMG" | _filter_qemu_io
 }
 
 function do_io() {
@@ -46,18 +46,18 @@ function do_io() {
 }
 
 function io_pattern() {
-    do_io "$@" | $QEMU_IO $TEST_IMG | _filter_qemu_io
+    do_io "$@" | $QEMU_IO "$TEST_IMG" | _filter_qemu_io
 }
 
 function io() {
     local start=$2
     local pattern=$(( (start >> 9) % 256 ))
 
-    do_io "$@" $pattern | $QEMU_IO $TEST_IMG | _filter_qemu_io
+    do_io "$@" $pattern | $QEMU_IO "$TEST_IMG" | _filter_qemu_io
 }
 
 function io_zero() {
-    do_io "$@" 0 | $QEMU_IO $TEST_IMG | _filter_qemu_io
+    do_io "$@" 0 | $QEMU_IO "$TEST_IMG" | _filter_qemu_io
 }
 
 function io_test() {
@@ -117,8 +117,8 @@ function io_test2() {
     echo === Clusters to be compressed [3]
     io_pattern writev $((offset + 8 * $cluster_size)) $cluster_size $((9 * $cluster_size)) $num 165
 
-    mv $TEST_IMG $TEST_IMG.orig
-    $QEMU_IMG convert -f $IMGFMT -O $IMGFMT -c $TEST_IMG.orig $TEST_IMG
+    mv "$TEST_IMG" "$TEST_IMG.orig"
+    $QEMU_IMG convert -f $IMGFMT -O $IMGFMT -c "$TEST_IMG.orig" "$TEST_IMG"
 
     # Write the used clusters
     echo === Used clusters [1]