Generic/JumbledIncrementer: fix inconsistency

The name of the sniff uses "Incrementer", while the error message uses "Incrementor". This feels inconsistent.

Based on some light research, both terms can be used interchangable, so I'm proposing to make the error message consistent with the sniff name, as changing the sniff name would be a breaking change.

Author: jrfnl

src/Standards/Generic/Sniffs/CodeAnalysis/JumbledIncrementerSniff.php

@@ -88,7 +88,7 @@ public function process(File $phpcsFile, $stackPtr)
             $diff  = array_intersect($outer, $inner);
 
             if (count($diff) !== 0) {
-                $error = 'Loop incrementor (%s) jumbling with inner loop';
+                $error = 'Loop incrementer (%s) jumbling with inner loop';
                 $data  = [implode(', ', $diff)];
                 $phpcsFile->addWarning($error, $stackPtr, 'Found', $data);
             }