refactor: use grep -E instead of egrep

Author: kxxt

ci/run.sh

@@ -79,7 +79,7 @@ if [ "$QEMU" != "" ]; then
     -net user \
     -nographic \
     -vga none 2>&1 | tee "${CARGO_TARGET_DIR}/out.log"
-  exec egrep "^(PASSED)|(test result: ok)" "${CARGO_TARGET_DIR}/out.log"
+  exec grep -E "^(PASSED)|(test result: ok)" "${CARGO_TARGET_DIR}/out.log"
 fi
 
 if [ "$TARGET" = "s390x-unknown-linux-gnu" ]; then

ci/test-runner-linux

@@ -20,6 +20,6 @@ timeout 30s qemu-system-$arch \
   -append init=/run_prog.sh > output || true
 
 # remove kernel messages
-tr -d '\r' < output | egrep -v '^\['
+tr -d '\r' < output | grep -Ev '^\['
 
-egrep "(PASSED)|(test result: ok)" output > /dev/null
+grep -E "(PASSED)|(test result: ok)" output > /dev/null