selftests/ftrace: Fix check of return value in fgraph-retval.tc test

The addition of recording both the function name and return address to the
function graph tracer updated the selftest to check for "=-5" from "= -5".
But this causes the test to fail on certain configs, as "= -5" is still a
value that can be returned if function addresses are not enabled (older kernels).

Check for both "=-5" and " -5" as a success value.

Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Donglin Peng <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: 21e9280 ("function_graph: Support recording and printing the function return address")
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: rostedt

tools/testing/selftests/ftrace/test.d/ftrace/fgraph-retval.tc

@@ -29,7 +29,7 @@ set -e
 
 : "Test printing the error code in signed decimal format"
 echo 0 > options/funcgraph-retval-hex
-count=`cat trace | grep 'proc_reg_write' | grep '=-5' | wc -l`
+count=`cat trace | grep 'proc_reg_write' | grep -e '=-5 ' -e '= -5 '  | wc -l`
 if [ $count -eq 0 ]; then
     fail "Return value can not be printed in signed decimal format"
 fi