[gdb/testsuite] Fix gdb_load_no_complaints with gnu-debuglink

When running test-case gdb.dwarf2/dw2-ranges-psym-warning.exp with target
board gnu-debuglink I run into:
...
(gdb) file dw2-ranges-psym-warning^M
Reading symbols from dw2-ranges-psym-warning...^M
Reading symbols from .debug/dw2-ranges-psym-warning.debug...^M
(gdb) FAIL: gdb.dwarf2/dw2-ranges-psym-warning.exp: No complaints
...

Fix this by updating the regexp in gdb_load_no_complaints.

Tested on x86_64-linux.
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 926c332..929e6b1 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -5406,8 +5406,8 @@
     # Verify that there were no complaints.
     set re \
 	[multi_line \
-	     "^Reading symbols from \[^\r\n\]*" \
-	     "(Expanding full symbols from \[^\r\n\]*" \
+	     "^(Reading symbols from \[^\r\n\]*" \
+	     ")+(Expanding full symbols from \[^\r\n\]*" \
 	     ")?$gdb_prompt $"]
     gdb_assert {[regexp $re $gdb_file_cmd_msg]} "No complaints"
 }