Fix typo

Change-Id: I1413e1872b1f2cd29256b33cdc7ac7ae09faf46c
Reviewed-on: https://gerrit.libreoffice.org/70394
Tested-by: Jenkins
Reviewed-by: Julien Nabet <serval2412@yahoo.fr>

basic/source/sbx/sbxform.cxx

@@ -115,7 +115,7 @@ SbxBasicFormater::SbxBasicFormater( sal_Unicode _cDecPoint, sal_Unicode _cThousa
 {
 }
 
-// function for output of a error-text (for debugging)
+// function to output an error-text (for debugging)
 // displaces all characters of the string, starting from nStartPos
 // for one position to larger indexes, i. e. place for a new
 // character (which is to be inserted) is created.