builtin: remove errant space in hyphenated adjective phrase

Change-Id: I67947e0e3189093e830120941ee49f9f32086f0e
Reviewed-on: https://go-review.googlesource.com/11615
Reviewed-by: Rob Pike <r@golang.org>

Author: bradfitz

src/builtin/builtin.go

@@ -236,14 +236,14 @@ func panic(v interface{})
 // panicking.
 func recover() interface{}
 
-// The print built-in function formats its arguments in an implementation-
-// specific way and writes the result to standard error.
+// The print built-in function formats its arguments in an
+// implementation-specific way and writes the result to standard error.
 // Print is useful for bootstrapping and debugging; it is not guaranteed
 // to stay in the language.
 func print(args ...Type)
 
-// The println built-in function formats its arguments in an implementation-
-// specific way and writes the result to standard error.
+// The println built-in function formats its arguments in an
+// implementation-specific way and writes the result to standard error.
 // Spaces are always added between arguments and a newline is appended.
 // Println is useful for bootstrapping and debugging; it is not guaranteed
 // to stay in the language.