gdb/dap: use breakpoint fullname to resolve source

If the breakpoint has a fullname, use that as the source path when
resolving the breakpoint source information. This is consistent with
other callers of make_source which also use "fullname" if it exists (see
e.g. DAPFrameDecorator which returns the symtab's fullname).

Approved-By: Tom Tromey <tom@tromey.com>
diff --git a/gdb/python/lib/gdb/dap/breakpoint.py b/gdb/python/lib/gdb/dap/breakpoint.py
index bf06298..8518814 100644
--- a/gdb/python/lib/gdb/dap/breakpoint.py
+++ b/gdb/python/lib/gdb/dap/breakpoint.py
@@ -108,6 +108,9 @@
         loc = bp.locations[0]
         if loc.source:
             (filename, line) = loc.source
+            if loc.fullname is not None:
+                filename = loc.fullname
+
             result.update(
                 {
                     "source": make_source(filename, os.path.basename(filename)),
@@ -118,9 +121,6 @@
         if loc.address:
             result["instructionReference"] = hex(loc.address),
 
-        path = loc.fullname
-        if path is not None:
-            result["source"]["path"] = path
     return result