audit: system check fixed for multiple arguments

Closes Homebrew/homebrew#35459.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Library/Homebrew/cmd/audit.rb

@@ -552,7 +552,7 @@ class FormulaAuditor
     end
 
     if @strict
-      if line =~ /system (["'][^"' ]*\s[^"' ]*["'])/
+      if line =~ /system (["'][^"' ]*(?:\s[^"' ]*)+["'])/
         bad_system = $1
         good_system = bad_system.gsub(" ", "\", \"")
         problem "Use `system #{good_system}` instead of `system #{bad_system}` "