rpi-eeprom-update: Fix shellcheck warnings

rpi-eeprom-update

@@ -104,7 +104,7 @@ die() {
 
 prepareImage()
 {
-   [ -f "${BOOTLOADER_UPDATE_IMAGE}" ] || die "EEPROM image \'${BOOTLOADER_UPDATE_IMAGE}\' not found"
+   [ -f "${BOOTLOADER_UPDATE_IMAGE}" ] || die "EEPROM image '${BOOTLOADER_UPDATE_IMAGE}' not found"
    TMP_EEPROM_IMAGE="$(mktemp)"
    TMP_EEPROM_CONFIG="$(mktemp)"
    NEW_EEPROM_CONFIG="$(mktemp)"
@@ -180,7 +180,7 @@ applyRecoveryUpdate()
                 || die "Failed to create ${BOOTFS}/vl805.sig"
 
         cp -f "${VL805_UPDATE_IMAGE}" "${BOOTFS}/vl805.bin" \
-                || die "Failed to copy ${VL805_UPDATE_IMAGE} to ${BOOTFS/vl805.bin}"
+                || die "Failed to copy ${VL805_UPDATE_IMAGE} to ${BOOTFS}/vl805.bin"
 
         # For NFS mounts ensure that the files are readable to the TFTP user
         chmod -f go+r "${BOOTFS}/vl805.bin" "${BOOTFS}/vl805.sig" \
@@ -205,7 +205,7 @@ applyUpdate() {
          fi
 
          CHECKSUMS=$(mktemp)
-         cat "${package_checksums_file}" | grep -E '\.bin$' > "${CHECKSUMS}"
+         grep -E '\.bin$' "${package_checksums_file}" > "${CHECKSUMS}"
          cd /
          if ! md5sum -c "${CHECKSUMS}" > /dev/null 2>&1; then
             md5sum -c "${CHECKSUMS}"
@@ -304,7 +304,7 @@ checkDependencies() {
    BOARD_TYPE=$(((0x$BOARD_INFO >> 4) & 0xff))
    BOARD_REVISION=$((0x$BOARD_INFO & 0xf))
 
-   if [ ${BOARD_TYPE} -eq 20 ] && [ ${CM4_ENABLE_RPI_EEPROM_UPDATE} != '1' ]; then
+   if [ ${BOARD_TYPE} -eq 20 ] && [ "${CM4_ENABLE_RPI_EEPROM_UPDATE}" != '1' ]; then
       # For CM4, USB device boot is the recommended method for EEPROM updates.
       echo "rpi-eeprom-update is not enabled by default on CM4"
       exit ${EXIT_SUCCESS}
@@ -722,9 +722,9 @@ while getopts A:abdhilf:m:ju:r option; do
    a) AUTO_UPDATE_BOOTLOADER=1
       AUTO_UPDATE_VL805=1
       ;;
-   b) 
-      findBootFS    
-      echo ${BOOTFS}
+   b)
+      findBootFS
+      echo "${BOOTFS}"
       exit 0
       ;;
    d) OVERWRITE_CONFIG=1