fsx: fix indenting of columns in bad buffers report

fsx: fix indenting of columns in bad buffers report

When file corruption is detected, make the columns of the report line
up correctly even in the diff output.  Although the .out.bad file
contains this (with spaces to demonstrate unequivocally what happens
when tabs are formatted as 8-column indent):

OFFSET  GOOD    BAD     RANGE
0x2c000 0x0000  0xd6c1  0x00000

diffing the good and bad golden output yields poorly formatted output:

+OFFSET GOOD    BAD     RANGE
+0x2c000        0x0000  0xd6c1  0x00000

Replace the tabs with columns indented with printf width specifiers so
that the test output gets this:

OFFSET      GOOD    BAD     RANGE
0x2c000     0x0000  0xd6c1  0x0

...which always lines up the columns regardless of the user's tab
display settings or diff inserting plus signs.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>