Add u8 array to float conversion check

Signed-off-by: Won Jeon <won.jeon@arm.com>
Change-Id: Idfd668b0ce8f8f587e00ca7b03063ce58d789ac4
diff --git a/include/attribute.h b/include/attribute.h
index 952b030..1a19f62 100644
--- a/include/attribute.h
+++ b/include/attribute.h
@@ -67,7 +67,7 @@
 #define DEF_ARGS_VER0_S_float_as_bytes(V)                                                                              \
     {                                                                                                                  \
         std::vector<float> attr_vec;                                                                                   \
-        if (convertFlatbuffersU8toF32(*(p->V()), 1, attr_vec))                                                         \
+        if (p->V() && convertFlatbuffersU8toF32(*(p->V()), 1, attr_vec))                                               \
             assert(0 && "Failed to convert u8 buffer to f32");                                                         \
         _##V = (!attr_vec.empty()) ? attr_vec[0] : 0.0f;                                                               \
     }