[gdb/testsuite] Fix typo in proc lines

Proc lines contains a typo:
...
  string_form { set $_line_string_form $value }
...

Remove the incorrect '$' in '$_line_string_form'.

Tested on x86_64-linux.

1 files changed, 1 insertions, 1 deletions

diff --git a/gdb/testsuite/lib/dwarf.exp b/gdb/testsuite/lib/dwarf.exp
index 94f6765..96978b8 100644
--- a/gdb/testsuite/lib/dwarf.exp
+++ b/gdb/testsuite/lib/dwarf.exp
@@ -2209,7 +2209,7 @@ namespace eval Dwarf {
 		addr_size { set _unit_addr_size $value }
 		seg_sel_size { set _seg_sel_size $value }
 		default_is_stmt { set _default_is_stmt $value }
-		string_form { set $_line_string_form $value }
+		string_form { set _line_string_form $value }
 		default { error "unknown option $name" }
 	    }
 	}