tc: allow 0% for percent options

Allowing 0% is sometimes useful for example in netem loss and drop
or perhaps dropping all traffic in a HTB bin.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199745
Reported-by: stuartmarsden@gmail.com
Fixes: 927e3cfb52 ("tc: B.W limits can now be specified in %.")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

lib/utils.c

@@ -105,7 +105,7 @@ int parse_percent(double *val, const char *str)
 	*val = strtod(str, &p) / 100.;
 	if (*val == HUGE_VALF || *val == HUGE_VALL)
 		return 1;
-	if (*val == 0.0 || (*p && strcmp(p, "%")))
+	if (*p && strcmp(p, "%"))
 		return -1;
 
 	return 0;