xbps-src: adjust help for -s

it's now used for python dependency verification too

Author: classabbyamp

xbps-src

@@ -244,7 +244,7 @@ $(print_cross_targets)
     This alternative repository will also be used to resolve dependencies
     with highest priority order than others.
 
--s  Make vsed warnings errors.
+-s  Make some warnings into errors.
 
 -t  Create a temporary masterdir to not pollute the current one. Note that
     the existing masterdir must be fully populated with binary-bootstrap first.