[PATCH] generic/{175,297,298}: fix use of uninitialized var

[Amir Goldstein <amir73il@gmail.com>]

Not sure how those tests pass in regression tests.
Probably truncate silently fails and is not critical to the test.

in kdevops I get errors like:
/data/fstests-install/xfstests/tests/generic/298: line 45: /dev/loop12):
           syntax error: operand expected (error token is "/dev/loop12)")

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 tests/generic/175 | 2 +-
 tests/generic/297 | 2 +-
 tests/generic/298 | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/generic/175 b/tests/generic/175
index 07af2199..14825a39 100755
--- a/tests/generic/175
+++ b/tests/generic/175
@@ -33,7 +33,7 @@ _pwrite_byte 0x61 0 $blksz "$testdir/file1" >> "$seqres.full"
 
 fnr=19
 echo "Create extents"
-truncate -s $(( (2 ** i) * blksz)) "$testdir/file1"
+truncate -s $(( (2 ** (fnr + 1)) * blksz)) "$testdir/file1"
 for i in $(seq 0 $fnr); do
 	echo " ++ Reflink size $i, $((2 ** i)) blocks" >> "$seqres.full"
 	n=$(( (2 ** i) * blksz))
diff --git a/tests/generic/297 b/tests/generic/297
index 6bdc3e1c..1fc48671 100755
--- a/tests/generic/297
+++ b/tests/generic/297
@@ -42,7 +42,7 @@ _pwrite_byte 0x61 0 $blksz $testdir/file1 >> $seqres.full
 fnr=26		# 2^26 reflink extents should be enough to find a slow op?
 timeout=8	# guarantee a good long run...
 echo "Find a reflink size that takes a long time"
-truncate -s $(( (2 ** i) * blksz)) $testdir/file1
+truncate -s $(( (2 ** (fnr + 1)) * blksz)) $testdir/file1
 for i in $(seq 0 $fnr); do
 	echo " ++ Reflink size $i, $((2 ** i)) blocks" >> $seqres.full
 	n=$(( (2 ** i) * blksz))
diff --git a/tests/generic/298 b/tests/generic/298
index 95d4c02b..2e917a87 100755
--- a/tests/generic/298
+++ b/tests/generic/298
@@ -42,7 +42,7 @@ _pwrite_byte 0x61 0 $blksz $testdir/file1 >> $seqres.full
 fnr=26		# 2^26 reflink extents should be enough to find a slow op?
 timeout=8	# guarantee a good long run...
 echo "Find a reflink size that takes a long time"
-truncate -s $(( (2 ** i) * blksz)) $testdir/file1
+truncate -s $(( (2 ** (fnr + 1)) * blksz)) $testdir/file1
 for i in $(seq 0 $fnr); do
 	echo " ++ Reflink size $i, $((2 ** i)) blocks" >> $seqres.full
 	n=$(( (2 ** i) * blksz))
-- 
2.34.1