selftests/x86/fsgsbase: Fix a comment in the ptrace_write_gsbase test

A comment was unclear.  Fix it.

Fixes: 5e7ec85 ("selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/901034a91a40169ec84f1f699ea86704dff762e4.1593192140.git.luto@kernel.org

Author: amluto

tools/testing/selftests/x86/fsgsbase.c

@@ -498,7 +498,8 @@ static void test_ptrace_write_gsbase(void)
 			 * base would zero the selector.  On newer kernels,
 			 * this behavior has changed -- poking the base
 			 * changes only the base and, if FSGSBASE is not
-			 * available, this may not effect.
+			 * available, this may have no effect once the tracee
+			 * is resumed.
 			 */
 			if (gs == 0)
 				printf("\tNote: this is expected behavior on older kernels.\n");