Fix node-mixin prometheus alert rules to use percentage

Signed-off-by: Leo <leonardjonathanoh@live.com>

docs/node-mixin/alerts/alerts.libsonnet

@@ -8,7 +8,7 @@
             alert: 'NodeFilesystemSpaceFillingUp',
             expr: |||
               (
-                node_filesystem_avail_bytes{%(nodeExporterSelector)s,%(fsSelector)s} / node_filesystem_size_bytes{%(nodeExporterSelector)s,%(fsSelector)s} < 0.4
+                node_filesystem_avail_bytes{%(nodeExporterSelector)s,%(fsSelector)s} / node_filesystem_size_bytes{%(nodeExporterSelector)s,%(fsSelector)s} * 100 < 40
               and
                 predict_linear(node_filesystem_avail_bytes{%(nodeExporterSelector)s,%(fsSelector)s}[6h], 24*60*60) < 0
               and
@@ -28,7 +28,7 @@
             alert: 'NodeFilesystemSpaceFillingUp',
             expr: |||
               (
-                node_filesystem_avail_bytes{%(nodeExporterSelector)s,%(fsSelector)s} / node_filesystem_size_bytes{%(nodeExporterSelector)s,%(fsSelector)s} < 0.2
+                node_filesystem_avail_bytes{%(nodeExporterSelector)s,%(fsSelector)s} / node_filesystem_size_bytes{%(nodeExporterSelector)s,%(fsSelector)s} * 100 < 20
               and
                 predict_linear(node_filesystem_avail_bytes{%(nodeExporterSelector)s,%(fsSelector)s}[6h], 4*60*60) < 0
               and
@@ -84,7 +84,7 @@
             alert: 'NodeFilesystemFilesFillingUp',
             expr: |||
               (
-                node_filesystem_files_free{%(nodeExporterSelector)s,%(fsSelector)s} / node_filesystem_files{%(nodeExporterSelector)s,%(fsSelector)s} < 0.4
+                node_filesystem_files_free{%(nodeExporterSelector)s,%(fsSelector)s} / node_filesystem_files{%(nodeExporterSelector)s,%(fsSelector)s} * 100 < 40
               and
                 predict_linear(node_filesystem_files_free{%(nodeExporterSelector)s,%(fsSelector)s}[6h], 24*60*60) < 0
               and
@@ -104,7 +104,7 @@
             alert: 'NodeFilesystemFilesFillingUp',
             expr: |||
               (
-                node_filesystem_files_free{%(nodeExporterSelector)s,%(fsSelector)s} / node_filesystem_files{%(nodeExporterSelector)s,%(fsSelector)s} < 0.2
+                node_filesystem_files_free{%(nodeExporterSelector)s,%(fsSelector)s} / node_filesystem_files{%(nodeExporterSelector)s,%(fsSelector)s} * 100 < 20
               and
                 predict_linear(node_filesystem_files_free{%(nodeExporterSelector)s,%(fsSelector)s}[6h], 4*60*60) < 0
               and