grasp_ros2: fixed CMake issue

correct typo for 'pcl_conversions'

Signed-off-by: Sharron LIU <sharron.xr.liu@gmail.com>

Author: sharronliu

grasp_ros2/tests/CMakeLists.txt

@@ -3,6 +3,7 @@ find_package(ament_cmake_gtest REQUIRED)
 find_package(rclcpp REQUIRED)
 find_package(grasp_msgs REQUIRED)
 find_package(moveit_msgs REQUIRED)
+find_package(pcl_conversions REQUIRED)
 set(TEST_NAME tgrasp_ros2)
 
 ament_add_gtest(${TEST_NAME} tgrasp_ros2.cpp ${CMAKE_CURRENT_SOURCE_DIR}/../src/consts.cpp)
@@ -16,7 +17,7 @@ if(TARGET ${TEST_NAME})
     ${grasp_library_INCLUDE_DIRS}
   )
   ament_target_dependencies(${TEST_NAME}
-    pcl_conversion
+    pcl_conversions
     rclcpp
     grasp_msgs
     moveit_msgs