gcc.misc-tests/outputs.exp (outest): Fix typo "is_target".

gcc.misc-tests/outputs.exp (outest): Fix typo "is_target".

Fix typo for istarget in "is_target hppa*-*-hpux*", yielding
an error running the test-suite for any target not matching
powerpc*-*-aix* (presumably, by code inspection), aborting
the check-gcc (check-gcc-c) regression test run some 3000
tests before the last one, missing e.g. all gcc.target
tests like so:

-----
...
Running /x/gcc/gcc/testsuite/gcc.misc-tests/outputs.exp ...
ERROR: (DejaGnu) proc "is_target hppa*-*-hpux*" does not exist.
The error code is TCL LOOKUP COMMAND is_target
The info on the error is:
invalid command name "is_target"
    while executing
"::tcl_unknown is_target hppa*-*-hpux*"
    ("uplevel" body line 1)
    invoked from within
"uplevel 1 ::tcl_unknown $args"

		=== gcc Summary ===
...
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gcc/testsuite:
	* gcc.misc-tests/outputs.exp (outest): Fix typo "is_target".