tf-a-next: cope with new RF-A tree layout

Since RF-A commit "chore(rust): move all RF-A files to the top
directory", the rust/ directory does not exist anymore. Update the
`build_package.sh` and static checks scripts to cope with that.

Signed-off-by: Sandrine Afsa <sandrine.afsa@arm.com>
Change-Id: I2bafffa5742119a6439a8902c0d486fcd30d8f18
diff --git a/script/next-checks/next-checks-clippy.sh b/script/next-checks/next-checks-clippy.sh
index 167bab9..e851abb 100755
--- a/script/next-checks/next-checks-clippy.sh
+++ b/script/next-checks/next-checks-clippy.sh
@@ -19,7 +19,7 @@
 echo >> "$LOG_TEST_FILENAME"
 echo "Platforms:" >> "$LOG_TEST_FILENAME"
 
-available_platforms=$(make --silent -C ${TF_ROOT}/rust list_platforms)
+available_platforms=$(make --silent -C ${TF_ROOT} list_platforms)
 
 # Run clippy for all platforms
 for plat in $available_platforms
@@ -27,7 +27,7 @@
     echo >> $LOG_FILE
     echo "############### ${TEST_CASE} - platform: ${plat}" >> "$LOG_FILE"
     echo >> $LOG_FILE
-    make -C ${TF_ROOT}/rust PLAT=${plat} clippy >> "$LOG_FILE" 2>&1
+    make -C ${TF_ROOT} PLAT=${plat} clippy >> "$LOG_FILE" 2>&1
 
     if [ "$?" -ne 0 ]; then
         echo -e "  ${plat}\t: FAIL" >> "$LOG_TEST_FILENAME"
@@ -41,7 +41,7 @@
 echo >> $LOG_FILE
 echo "############### ${TEST_CASE} - platform: tests" >> "$LOG_FILE"
 echo >> $LOG_FILE
-make -C ${TF_ROOT}/rust clippy-test >> "$LOG_FILE" 2>&1
+make -C ${TF_ROOT} clippy-test >> "$LOG_FILE" 2>&1
 
 if [ "$?" -ne 0 ]; then
     echo -e "  clippy-test\t: FAIL" >> "$LOG_TEST_FILENAME"