Fix fatal typo in gcc.dg/no_profile_instrument_function-attr-2.c

Fix fatal typo in gcc.dg/no_profile_instrument_function-attr-2.c

Dejagnu is unfortunately brittle: a syntax error in a
directive can abort the test-run for the current "tool"
(gcc, g++, gfortran), and if you don't check for this
condition or actually read the stdout log yourself, your
tools may make you believe the test was successful without
regressions.  At the very least, always grep for ^ERROR: in
the stdout log!

With r12-3379, the testsuite got such a fatal syntax error,
causing the gcc test-run to abort at (e.g.):

...
FAIL: gcc.dg/memchr.c (test for excess errors)
FAIL: gcc.dg/memcmp-3.c (test for excess errors)
ERROR: (DejaGnu) proc "scan-tree-dump-not\" = foo {\(\)"} optimized" does not exist.
The error code is TCL LOOKUP COMMAND scan-tree-dump-not\"
The info on the error is:
invalid command name "scan-tree-dump-not""
    while executing
"::tcl_unknown scan-tree-dump-not\" = foo {\(\)"} optimized"
    ("uplevel" body line 1)
    invoked from within
"uplevel 1 ::tcl_unknown $args"

		=== gcc Summary ===

# of expected passes		63740
# of unexpected failures	38
# of unexpected successes	2
# of expected failures		351
# of unresolved testcases	3
# of unsupported tests		662
x/cris-elf/gccobj/gcc/xgcc  version 12.0.0 20210907 (experimental)\
 [master r12-3391-g849d5f5929fc] (GCC)

testsuite:
	* gcc.dg/no_profile_instrument_function-attr-2.c: Fix
	typo in last change.