Grammar: Fix var x = init(...) highlighting

This fixes change introduced in a8328ab that
was adding type highlighting in `var x Type`. However the rule (.*)\s*(?:=|$)
was greedy consuming everything until `=` or `$` (end of line). As a
consequence it was effectively matching everything till end of line, consuming
also `=` and everything that follows, resulting incorrect highlight, for eg.:

  var addr = flag.String("addr", ":8080", "TCP address to listen to")

Now replacing RE to use lazy (non-greedy) (.*?)\s*(?:=|$) rule.

Author: nanoant

Syntaxes/Go.tmLanguage

@@ -469,7 +469,7 @@
 					<key>comment</key>
 					<string>This matches the 'var x' style of variable declaration.</string>
 					<key>match</key>
-					<string>^\s*(var)\s+((?:[[:alpha:]_]\w*)(?:,\s+[[:alpha:]_]\w*)*)\s*(.*)\s*(?:=|$)</string>
+					<string>^\s*(var)\s+((?:[[:alpha:]_]\w*)(?:,\s+[[:alpha:]_]\w*)*)\s*(.*?)\s*(?:=|$)</string>
 					<key>name</key>
 					<string>meta.initialization.explicit.go</string>
 				</dict>