[committed][gdb/testsuite] Fix gdb.fortran/nested-funcs-2.exp with gdbserver

[Tom de Vries <tdevries@suse.de>]

Hi,

When running test-case gdb.fortran/nested-funcs-2.exp with target board
native-gdbserver, we have:
...
(gdb) call contains_keyword::subroutine_to_call()^M
(gdb) FAIL: gdb.fortran/nested-funcs-2.exp: src_prefix=0: nest_prefix=1: \
  call contains_keyword::subroutine_to_call()
...

This is caused by the fact that we're trying to match inferior output using
gdb_test.

Fix this by using gdb_test_stdio instead.

Tested on x86_64-linux.

Committed to trunk.

Thanks,
- Tom

[gdb/testsuite] Fix gdb.fortran/nested-funcs-2.exp with gdbserver

gdb/testsuite/ChangeLog:

2020-05-14  Tom de Vries  <tdevries@suse.de>

	* gdb.fortran/nested-funcs-2.exp: Use gdb_test_stdio to test inferior
	output.

---
 gdb/testsuite/gdb.fortran/nested-funcs-2.exp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.fortran/nested-funcs-2.exp b/gdb/testsuite/gdb.fortran/nested-funcs-2.exp
index 724be74ff8..4e517bba2f 100644
--- a/gdb/testsuite/gdb.fortran/nested-funcs-2.exp
+++ b/gdb/testsuite/gdb.fortran/nested-funcs-2.exp
@@ -89,7 +89,7 @@ proc do_bp_tests {with_src_prefix_p with_nest_prefix_p} {
 
     # Call a contained function.
     if { ${with_nest_prefix_p} } {
-	gdb_test "call ${nest_prefix}subroutine_to_call()" " called"
+	gdb_test_stdio "call ${nest_prefix}subroutine_to_call()" " called" ""
     }
 
     # Break on another contained function and run to it.