generic: fix $tmp path in tests

Some tests use "tmp/$$" as $tmp, and this would result in ENOENT
failure if $tmp is referenced in helpers or tests, because we have
no "tmp" dir in pwd.

Fix them to use "/tmp/$$" as all other tests do.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

tests/generic/018

@@ -26,7 +26,7 @@ seqres=$RESULT_DIR/$seq
 echo "QA output created by $seq"
 
 here=`pwd`
-tmp=tmp/$$
+tmp=/tmp/$$
 status=1	# failure is the default!
 trap "_cleanup; exit \$status" 0 1 2 3 15
 

tests/generic/094

@@ -26,7 +26,7 @@ seqres=$RESULT_DIR/$seq
 echo "QA output created by $seq"
 
 here=`pwd`
-tmp=tmp/$$
+tmp=/tmp/$$
 status=1  # failure is the default!
 trap "_cleanup; exit \$status" 0 1 2 3 15
 

tests/generic/225

@@ -26,7 +26,7 @@ seqres=$RESULT_DIR/$seq
 echo "QA output created by $seq"
 
 here=`pwd`
-tmp=tmp/$$
+tmp=/tmp/$$
 status=1  # failure is the default!
 trap "_cleanup; exit \$status" 0 1 2 3 15
 

tests/generic/249

@@ -26,7 +26,7 @@ seqres=$RESULT_DIR/$seq
 echo "QA output created by $seq"
 
 here=`pwd`
-tmp=tmp/$$
+tmp=/tmp/$$
 status=1  # failure is the default!
 trap "_cleanup; exit \$status" 0 1 2 3 15