opencl: Add missing argument for L_WARNING

gcc report:

In file included from /usr/include/leptonica/alltypes.h:36:0,
                 from /usr/include/leptonica/allheaders.h:34,
                 from openclwrapper.h:2,
                 from openclwrapper.cpp:11:
openclwrapper.cpp: In static member function 'static PIX* OpenclDevice::pixReadMemTiffCl(const l_uint8*, size_t, l_int32)':
/usr/include/leptonica/environ.h:442:68: warning: format '%d' expects a matching 'int' argument [-Wformat=]
              (void)fprintf(stderr, "Warning in %s: " a, __VA_ARGS__), \
                                                                    ^
/usr/include/leptonica/environ.h:427:61: note: in definition of macro 'IF_SEV'
       ((l) >= MINIMUM_SEVERITY && (l) >= LeptMsgSeverity ? (t) : (f))
                                                             ^
opencl/openclwrapper.cpp:1162:3: note: in expansion of macro 'L_WARNING'
   L_WARNING("tiff page %d not found", procName);
   ^

Signed-off-by: Stefan Weil <sw@weilnetz.de>

opencl/openclwrapper.cpp

@@ -1159,7 +1159,7 @@ OpenclDevice::pixReadMemTiffCl(const l_uint8 *data,size_t size,l_int32  n)
 	}
 
 	if (pagefound == FALSE) {
-		L_WARNING("tiff page %d not found", procName);
+		L_WARNING("tiff page %d not found", procName, i);
 		TIFFCleanup(tif);
 		return NULL;
 	}