Spelling fixes

Spelling errors found using github.com/lucasdemarchi/codespell
A tool to fix common misspellings.
This tool is licensed under GNU General Public License, version 2.

Change-Id: I78e9d126f19fd9fb2e3f2fa9fe8c2404dc505f82
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/storageaddsel.cpp b/storageaddsel.cpp
index bd48edc..3232406 100644
--- a/storageaddsel.cpp
+++ b/storageaddsel.cpp
@@ -65,7 +65,7 @@
 
 	if ((r < 0) || (a.bus[0] == 0)) {
 		// Just make a generic message for errors that
-		// occur on sensors that dont exist
+		// occur on sensors that don't exist
 		r = asprintf(s, "Unknown Sensor (0x%02x)", sensor_number);
 	} else {