backends: Simplify loop getting rpaths for bundled libs

No functionality changes

mesonbuild/backend/backends.py

@@ -334,9 +334,11 @@ class Backend:
     def rpaths_for_bundled_shared_libraries(self, target):
         paths = []
         for dep in target.external_deps:
-            if isinstance(dep, (dependencies.ExternalLibrary, dependencies.PkgConfigDependency)):
+            if not isinstance(dep, (dependencies.ExternalLibrary, dependencies.PkgConfigDependency)):
+                continue
             la = dep.link_args
-                if len(la) == 1 and os.path.isabs(la[0]):
+            if len(la) != 1 or not os.path.isabs(la[0]):
+                continue
             # The only link argument is an absolute path to a library file.
             libpath = la[0]
             if libpath.startswith(('/usr/lib', '/lib')):