Fix misspellings using 'codespell' tool

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/tools/fio_generate_plots b/tools/fio_generate_plots
index 51c0643..a47bfa5 100755
--- a/tools/fio_generate_plots
+++ b/tools/fio_generate_plots
@@ -7,7 +7,7 @@
 #
 # The script uses the files generated by FIO to create nice graphs in the
 # SVG format. This output format is supported by most modern browsers and
-# allows resolution independant graphs to be generated.
+# allows resolution independent graphs to be generated.
 #
 # This script supports GNUPLOT 4.4 and higher.
 #