core(ocl): fix deadlock in UMatDataAutoLock

UMatData locks are not mapped on real locks (they are mapped to some "pre-initialized" pool).

Concurrent execution of these statements may lead to deadlock:
- a.copyTo(b) from thread 1
- c.copyTo(d) from thread 2
where:
- 'a' and 'd' are mapped to single lock "A".
- 'b' and 'c' are mapped to single lock "B".

Workaround is to process locks with strict order.

modules/core/include/opencv2/core/mat.hpp

@@ -545,14 +545,6 @@ struct CV_EXPORTS UMatData
 };
 
 
-struct CV_EXPORTS UMatDataAutoLock
-{
-    explicit UMatDataAutoLock(UMatData* u);
-    ~UMatDataAutoLock();
-    UMatData* u;
-};
-
-
 struct CV_EXPORTS MatSize
 {
     explicit MatSize(int* _p);

modules/core/include/opencv2/core/mat.inl.hpp

@@ -3911,9 +3911,6 @@ inline void UMatData::markDeviceCopyObsolete(bool flag)
         flags &= ~DEVICE_COPY_OBSOLETE;
 }
 
-inline UMatDataAutoLock::UMatDataAutoLock(UMatData* _u) : u(_u) { u->lock(); }
-inline UMatDataAutoLock::~UMatDataAutoLock() { u->unlock(); }
-
 //! @endcond
 
 } //cv