Return std::string from gdb_bfd_errmsg

This changes gdb_bfd_errmsg to return a std::string, removing a
cleanup.  This approach may be slightly less efficient than the
previous code, but I don't believe this is very important in this
situation.

gdb/ChangeLog
2018-09-13  Tom Tromey  <tom@tromey.com>

	* utils.h (gdb_bfd_errmsg): Return std::string.
	* exec.c (exec_file_attach): Update.
	* compile/compile-object-load.c (compile_object_load): Update.
	* utils.c (gdb_bfd_errmsg): Return std::string.

1 files changed, 1 insertions, 1 deletions

diff --git a/gdb/exec.c b/gdb/exec.c
index 3023ff7..6e44b0e 100644
--- a/gdb/exec.c
+++ b/gdb/exec.c
@@ -362,7 +362,7 @@ exec_file_attach (const char *filename, int from_tty)
 	  exec_close ();
 	  error (_("\"%s\": not in executable format: %s"),
 		 scratch_pathname,
-		 gdb_bfd_errmsg (bfd_get_error (), matching));
+		 gdb_bfd_errmsg (bfd_get_error (), matching).c_str ());
 	}
 
       if (build_section_table (exec_bfd, &sections, &sections_end))