Report Full: remove duplicate function call

... and comment the code little more.

src/Reports/Full.php

@@ -64,24 +64,26 @@ public function generateFileReport($report, File $phpcsFile, $showSources=false,
         foreach ($report['messages'] as $line => $lineErrors) {
             foreach ($lineErrors as $column => $colErrors) {
                 foreach ($colErrors as $error) {
-                    $length = strlen($error['message']);
+                    // Start with the presumption of a single line error message.
+                    $length    = strlen($error['message']);
+                    $srcLength = (strlen($error['source']) + 3);
                     if ($showSources === true) {
-                        $length += (strlen($error['source']) + 3);
+                        $length += $srcLength;
                     }
 
-                    // Handle multi-line message correctly.
+                    // ... but also handle multi-line messages correctly.
                     if (strpos($error['message'], "\n") !== false) {
                         $errorLines = explode("\n", $error['message']);
                         $length     = max(array_map('strlen', $errorLines));
 
                         if ($showSources === true) {
                             $lastLine = array_pop($errorLines);
-                            $length   = max($length, (strlen($lastLine) + (strlen($error['source']) + 3)));
+                            $length   = max($length, (strlen($lastLine) + $srcLength));
                         }
                     }
 
                     $maxErrorLength = max($maxErrorLength, ($length + 1));
-                }
+                }//end foreach
             }//end foreach
         }//end foreach