selftests: breakpoints: Fix a typo of function name

Since commit 5821ba969511 ("selftests: Add test plan API to kselftest.h
and adjust callers") accidentally introduced 'a' typo in the front of
run_test() function, breakpoint_test_arm64.c became not able to be
compiled.

Remove the 'a' from arun_test().

Fixes: 5821ba969511 ("selftests: Add test plan API to kselftest.h and adjust callers")
Reported-by: Jun Takahashi <[e-mail]>
Signed-off-by: Masami Hiramatsu <[e-mail]>
Cc: Kees Cook <[e-mail]>
Reviewed-by: Kees Cook <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/breakpoints/breakpoint_test_arm64.c

···
 	return false;
 }
 
-static bool arun_test(int wr_size, int wp_size, int wr, int wp)
+static bool run_test(int wr_size, int wp_size, int wr, int wp)
 {
 	int status;
 	siginfo_t siginfo;