du01.sh: Fix failures on Btrfs on ppc32le

The ppc32le has 64k pagesize and due to Btrfs internal implementation
details the size of a symlink is reported to be a pagesize large. Hence
the test assertions 5 and 6 fails because the reported size is sligtly
larger.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>

testcases/commands/du/du01.sh

@@ -89,7 +89,7 @@ block_size=512
 check1="10[2-3][0-9][0-9][[:space:]]\."
 check2="10[2-3][0-9][0-9][[:space:]]testfile"
 check3="[0-4][[:space:]]\.\/testdir\/testsymlink"
-check5="20[4-5][0-9][0-9][[:space:]]\."
+check5="20[4-6][0-9][0-9][[:space:]]\."
 check7="10[4-5][0-9][0-9]\{4\}[[:space:]]\."
 check9="10[2-3][0-9][0-9][[:space:]]total"
 check11="10[2-3][0-9][0-9][[:space:]]testdir\/testsymlink"