fixup! settings: Handle return code correctly

Signed-off-by: Daniel Schultz <d.schultz@phytec.de>

settings/artix7.sh

diff --git a/settings/artix7.sh b/settings/artix7.sh
index d5f63df..97c57e6 100644
--- a/settings/artix7.sh
+++ b/settings/artix7.sh
@@ -33,7 +33,7 @@
 
 source $(dirname ${BASH_SOURCE[0]})/../utils/environment.sh
 
-env=`python3 ${XRAY_UTILS_DIR}/create_environment.py`
+env=$(python3 ${XRAY_UTILS_DIR}/create_environment.py)
 ENV_RET=$?
 if [[ $ENV_RET != 0 ]] ; then
 	return $ENV_RET

settings/artix7_200t.sh

diff --git a/settings/artix7_200t.sh b/settings/artix7_200t.sh
index 4ec566b..4f3b171 100644
--- a/settings/artix7_200t.sh
+++ b/settings/artix7_200t.sh
@@ -23,7 +23,7 @@
 
 source $(dirname ${BASH_SOURCE[0]})/../utils/environment.sh
 
-env=`python3 ${XRAY_UTILS_DIR}/create_environment.py`
+env=$(python3 ${XRAY_UTILS_DIR}/create_environment.py)
 ENV_RET=$?
 if [[ $ENV_RET != 0 ]] ; then
 	return $ENV_RET

settings/artix7_50t.sh

diff --git a/settings/artix7_50t.sh b/settings/artix7_50t.sh
index 7161514..0c0cf29 100644
--- a/settings/artix7_50t.sh
+++ b/settings/artix7_50t.sh
@@ -32,7 +32,7 @@
 
 source $(dirname ${BASH_SOURCE[0]})/../utils/environment.sh
 
-env=`python3 ${XRAY_UTILS_DIR}/create_environment.py`
+env=$(python3 ${XRAY_UTILS_DIR}/create_environment.py)
 ENV_RET=$?
 if [[ $ENV_RET != 0 ]] ; then
 	return $ENV_RET

settings/kintex7.sh

diff --git a/settings/kintex7.sh b/settings/kintex7.sh
index f7c16c8..85a705e 100644
--- a/settings/kintex7.sh
+++ b/settings/kintex7.sh
@@ -27,7 +27,7 @@
 
 source $(dirname ${BASH_SOURCE[0]})/../utils/environment.sh
 
-env=`python3 ${XRAY_UTILS_DIR}/create_environment.py`
+env=$(python3 ${XRAY_UTILS_DIR}/create_environment.py)
 ENV_RET=$?
 if [[ $ENV_RET != 0 ]] ; then
 	return $ENV_RET

settings/zynq7.sh

diff --git a/settings/zynq7.sh b/settings/zynq7.sh
index 716dd3f..1aed58a 100644
--- a/settings/zynq7.sh
+++ b/settings/zynq7.sh
@@ -29,7 +29,7 @@
 
 source $(dirname ${BASH_SOURCE[0]})/../utils/environment.sh
 
-env=`python3 ${XRAY_UTILS_DIR}/create_environment.py`
+env=$(python3 ${XRAY_UTILS_DIR}/create_environment.py)
 ENV_RET=$?
 if [[ $ENV_RET != 0 ]] ; then
 	return $ENV_RET

settings/zynq7010.sh

diff --git a/settings/zynq7010.sh b/settings/zynq7010.sh
index 4a9a883..9780fec 100644
--- a/settings/zynq7010.sh
+++ b/settings/zynq7010.sh
@@ -29,7 +29,7 @@
 
 source $(dirname ${BASH_SOURCE[0]})/../utils/environment.sh
 
-env=`python3 ${XRAY_UTILS_DIR}/create_environment.py`
+env=$(python3 ${XRAY_UTILS_DIR}/create_environment.py)
 ENV_RET=$?
 if [[ $ENV_RET != 0 ]] ; then
 	return $ENV_RET