configs/freescale: drop unneeded exit statement in post-image scripts

There is no need for the 'exit' statement in the post-image scripts,
so just remove it.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

board/freescale/imx25pdk/post-image.sh

@@ -12,5 +12,3 @@ genimage \
   --inputpath "${BINARIES_DIR}" \
   --outputpath "${BINARIES_DIR}" \
   --config "${GENIMAGE_CFG}"
-
-exit $?

board/freescale/imx51evk/post-image.sh

@@ -12,5 +12,3 @@ genimage \
   --inputpath "${BINARIES_DIR}" \
   --outputpath "${BINARIES_DIR}" \
   --config "${GENIMAGE_CFG}"
-
-exit $?

board/freescale/imx53loco/post-image.sh

@@ -12,5 +12,3 @@ genimage \
   --inputpath "${BINARIES_DIR}" \
   --outputpath "${BINARIES_DIR}" \
   --config "${GENIMAGE_CFG}"
-
-exit $?

board/freescale/imx6ulevk/post-image.sh

@@ -12,5 +12,3 @@ genimage \
   --inputpath "${BINARIES_DIR}" \
   --outputpath "${BINARIES_DIR}" \
   --config "${GENIMAGE_CFG}"
-
-exit $?

board/freescale/imx7dsdb/post-image.sh

@@ -12,5 +12,3 @@ genimage \
   --inputpath "${BINARIES_DIR}" \
   --outputpath "${BINARIES_DIR}" \
   --config "${GENIMAGE_CFG}"
-
-exit $?

board/technexion/imx6ulpico/post-image.sh

@@ -12,5 +12,3 @@ genimage \
   --inputpath "${BINARIES_DIR}" \
   --outputpath "${BINARIES_DIR}" \
   --config "${GENIMAGE_CFG}"
-
-exit $?