NFS storage pool: Fix libvirtd crash due to refactor edit

Commit id '18642d10' refactored the call to virCommandRunRegex()
inside a new function virStorageBackendFileSystemNetFindNFSPoolSources(),
but the cut-n-paste didn't remove the "&state".  Now that state is passed
by reference, it results in a libvirtd core with a messages entry:

"...internal error: unknown storage pool type Unknow"

src/storage/storage_backend_fs.c

@@ -266,7 +266,7 @@ virStorageBackendFileSystemNetFindNFSPoolSources(virNetfsDiscoverState *state)
 
     if (virCommandRunRegex(cmd, 1, regexes, vars,
                            virStorageBackendFileSystemNetFindPoolSourcesFunc,
-                           &state, NULL) < 0)
+                           state, NULL) < 0)
         virResetLastError();
 
     virCommandFree(cmd);