Merge pull request #15504 from NHZlX/fix_conv2d_fusion

Add check: conv_fusion op runs with cudnn version > 7100 .

paddle/fluid/inference/api/paddle_pass_builder.h

@@ -158,9 +158,12 @@ class GpuPassStrategy : public PassStrategy {
           "conv_affine_channel_fuse_pass",             //
           "conv_eltwiseadd_affine_channel_fuse_pass",  //
           "conv_bn_fuse_pass",                         //
+#if CUDNN_VERSION >= 7100  // To run conv_fusion, the version of cudnn must be
+                           // guaranteed at least v7
           "conv_elementwise_add_act_fuse_pass",   //
           "conv_elementwise_add2_act_fuse_pass",  //
           "conv_elementwise_add_fuse_pass",       //
+#endif
     });
 
     for (int i = 6; i >= 3; i--) {