Doc: fix definition of macro CV_MAKETYPE

At least this is how it's defined in core/types_c.h

Conflicts:
	modules/core/doc/intro.rst

modules/core/doc/intro.markdown

@@ -236,7 +236,7 @@ Multi-channel (n-channel) types can be specified using the following options:
     the number of channels is more than 4 or unknown at the compilation time.
 
 @note `CV_32FC1 == CV_32F, CV_32FC2 == CV_32FC(2) == CV_MAKETYPE(CV_32F, 2)`, and
-`CV_MAKETYPE(depth, n) == ((x&7)<<3) + (n-1)``. This means that the constant type is formed from the
+`CV_MAKETYPE(depth, n) == ((depth&7) + ((n-1)<<3)``. This means that the constant type is formed from the
 depth, taking the lowest 3 bits, and the number of channels minus 1, taking the next
 `log2(CV_CN_MAX)`` bits.