utest: UTEST_SLAB_TC -> RT_UTEST_SLAB

Signed-off-by: Chen Wang <unicorn_wang@outlook.com>

src/utest/Kconfig

@@ -16,7 +16,7 @@ config RT_UTEST_OBJECT
     bool "object test"
     default n
 
-config UTEST_SLAB_TC
+config RT_UTEST_SLAB
     bool "slab test"
     default n
     depends on RT_USING_SLAB

src/utest/SConscript

@@ -14,7 +14,7 @@ if GetDepend(['RT_UTEST_MEMHEAP']):
 if GetDepend(['RT_UTEST_SMALL_MEM']):
     src += ['mem_tc.c']
 
-if GetDepend(['UTEST_SLAB_TC']):
+if GetDepend(['RT_UTEST_SLAB']):
     src += ['slab_tc.c']
 
 if GetDepend(['UTEST_IRQ_TC']):