diff: correct warning message when renameLimit exceeded

The warning when quadratic rename detection was skipped referred to
"inexact rename detection".  For years, the only linear portion of
rename detection was looking for exact renames, so "inexact rename
detection" was an accurate way to refer to the quadratic portion of
rename detection.  However, that changed with commit bd24aa2
(diffcore-rename: guide inexact rename detection based on basenames,
2021-02-14).  Let's instead use the term "exhaustive rename detection"
to refer to the quadratic portion.

Signed-off-by: Elijah Newren <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: newren

diff.c

@@ -6284,7 +6284,7 @@ static int is_summary_empty(const struct diff_queue_struct *q)
 }
 
 static const char rename_limit_warning[] =
-N_("inexact rename detection was skipped due to too many files.");
+N_("exhaustive rename detection was skipped due to too many files.");
 
 static const char degrade_cc_to_c_warning[] =
 N_("only found copies from modified paths due to too many files.");