fix linting issues

run.sh

@@ -52,7 +52,7 @@ do
     echo failed to process "$FILE"
     mv "$FILE" "$FAILED_DIR"
     echo moved "$FILE" to "$FAILED_DIR"
-    FAILED_FILES+=${FILE}\n
+    FAILED_FILES+="${FILE}\n"
   fi
   echo
 done <   <(find "$SRC_DIR" -maxdepth 1 -name '*.pdf' -print0)
@@ -67,16 +67,14 @@ then
   echo "$FAILED_FILES"
 
   sendmail -t thomasruoff@gmail.com <<MAILTEXT
-  Subject: [$hostname] OCR on PDFs failed
+Subject: [$(hostname)] OCR on PDFs failed
 
-  Hey,
-  following PDFs failed to be OCR'd:
+Hey,
+following PDFs failed to be OCR'd:
+${FAILED_FILES}
 
-  ${FAILED_FILES}
-
-  Cheers
-
-  MAILTEXT
+Cheers
+MAILTEXT
 
 fi