zed: Control NVMe fault LEDs

The ZED code currently can only turn on the fault LED for
a faulted disk in a JBOD enclosure.  This extends support
for faulted NVMe disks as well.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #12648
Closes #12695

lib/libzutil/zutil_nicenum.c

@@ -27,6 +27,7 @@
 #include <math.h>
 #include <stdio.h>
 #include <libzutil.h>
+#include <string.h>
 
 /*
  * Return B_TRUE if "str" is a number string, B_FALSE otherwise.
@@ -42,6 +43,14 @@ zfs_isnumber(const char *str)
 		if (!(isdigit(*str) || (*str == '.')))
 			return (B_FALSE);
 
+	/*
+	 * Numbers should not end with a period ("." ".." or "5." are
+	 * not valid)
+	 */
+	if (str[strlen(str) - 1] == '.') {
+		return (B_FALSE);
+	}
+
 	return (B_TRUE);
 }