generic: fix check for zero range support in generic/009

Generic/001 fails when run on a file system that does not support byte range zeroing. For example, an EOPNOTSUPP failure occurs when the test is run on a pre-3.15 extent-mapped file system. The code in the test intended to prevent this contains an apparent typo that results in a check for fallocate() rather than zero range support.

v2: Use new helper function for the check.

---
 tests/generic/009 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index b7b0b3f..b4d3e4b 100644
@@ -44,7 +44,7 @@ trap "_cleanup ; exit \$status" 0 1 2 3 15
 
 # real QA test starts here
 _supported_os Linux
-_require_xfs_io_falloc "fzero"
+_require_xfs_io_falloc_zero
 
 testfile=$TEST_DIR/009.$$
 

1.8.3.2