testsuite: avoid "warning: stray \ before t" message

Grep (or maybe only some recent versions) complains when using the (wrong)
'\\t' pattern.

This pattern was used only once to check if the following pattern was at
the beginning of an instruction.

Prefer to use the more explicit '^.' pattern, already used in other tests.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
1 file changed