Apply zig fmt to exercises

exercises/07_strings2.zig

@@ -8,17 +8,17 @@
 //         \\Line One
 //         \\Line Two
 //     ;
-// 
+//
 // See if you can make this program print some song lyrics.
 //
 const std = @import("std");
 
 pub fn main() void {
-    const lyrics = 
+    const lyrics =
         Ziggy played guitar
         Jamming good with Andrew Kelley
         And the Spiders from Mars
     ;
 
-    std.debug.print("{s}\n",.{lyrics});
+    std.debug.print("{s}\n", .{lyrics});
 }