[tint] Fix syntax_tree build

Missing utils:: namespace on TrimSuffix().

Change-Id: I184bee79dc2c807730c1be0a532b290441d5f4ae
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/132323
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Ben Clayton <bclayton@google.com>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: James Price <jrprice@google.com>
Auto-Submit: Ben Clayton <bclayton@google.com>
diff --git a/src/tint/writer/syntax_tree/generator_impl.cc b/src/tint/writer/syntax_tree/generator_impl.cc
index 08ca8c5..56f7f57 100644
--- a/src/tint/writer/syntax_tree/generator_impl.cc
+++ b/src/tint/writer/syntax_tree/generator_impl.cc
@@ -976,14 +976,14 @@
                 case 0:  // No initializer
                     break;
                 case 1:  // Single line initializer statement
-                    line() << TrimSuffix(init_buf.lines[0].content, ";");
+                    line() << utils::TrimSuffix(init_buf.lines[0].content, ";");
                     break;
                 default:  // Block initializer statement
                     for (size_t i = 1; i < init_buf.lines.size(); i++) {
                         // Indent all by the first line
                         init_buf.lines[i].indent += current_buffer_->current_indent;
                     }
-                    line() << TrimSuffix(init_buf.String(), "\n");
+                    line() << utils::TrimSuffix(init_buf.String(), "\n");
                     break;
             }
         }
@@ -1004,14 +1004,14 @@
                 case 0:  // No continuing
                     break;
                 case 1:  // Single line continuing statement
-                    line() << TrimSuffix(cont_buf.lines[0].content, ";");
+                    line() << utils::TrimSuffix(cont_buf.lines[0].content, ";");
                     break;
                 default:  // Block continuing statement
                     for (size_t i = 1; i < cont_buf.lines.size(); i++) {
                         // Indent all by the first line
                         cont_buf.lines[i].indent += current_buffer_->current_indent;
                     }
-                    line() << TrimSuffix(cont_buf.String(), "\n");
+                    line() << utils::TrimSuffix(cont_buf.String(), "\n");
                     break;
             }
         }