remove uses of string concatenation from src and misc directory

R=rsc
https://golang.org/cl/172041
diff --git a/src/pkg/unicode/maketables.go b/src/pkg/unicode/maketables.go
index c96c12e..486742e 100644
--- a/src/pkg/unicode/maketables.go
+++ b/src/pkg/unicode/maketables.go
@@ -313,9 +313,9 @@
 		return;
 	}
 	fmt.Printf(
-		"// Generated by running\n"
-			"//	maketables --tables=%s --data=%s\n"
-			"// DO NOT EDIT\n\n"
+		"// Generated by running\n"+
+			"//	maketables --tables=%s --data=%s\n"+
+			"// DO NOT EDIT\n\n"+
 			"package unicode\n\n",
 		*tablelist,
 		*dataURL);
@@ -590,8 +590,8 @@
 	}
 
 	fmt.Printf(
-		"// Generated by running\n"
-			"//	maketables --%s=%s --url=%s\n"
+		"// Generated by running\n"+
+			"//	maketables --%s=%s --url=%s\n"+
 			"// DO NOT EDIT\n\n",
 		flag,
 		flaglist,
@@ -777,12 +777,12 @@
 		return;
 	}
 	fmt.Printf(
-		"// Generated by running\n"
-			"//	maketables --data=%s\n"
-			"// DO NOT EDIT\n\n"
-			"// CaseRanges is the table describing case mappings for all letters with\n"
-			"// non-self mappings.\n"
-			"var CaseRanges = _CaseRanges\n"
+		"// Generated by running\n"+
+			"//	maketables --data=%s\n"+
+			"// DO NOT EDIT\n\n"+
+			"// CaseRanges is the table describing case mappings for all letters with\n"+
+			"// non-self mappings.\n"+
+			"var CaseRanges = _CaseRanges\n"+
 			"var _CaseRanges = []CaseRange {\n",
 		*dataURL);