memblock test: Modify the obsolete description in README

The VERBOSE option in Makefile has been moved, but there still have the
description left in README. For now, we use `-v` options when running
memblock test to print information, so using the new to replace the
obsolete items.

Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com>
Acked-by: Rebecca Mckeever <remckee0@gmail.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20220729161125.190845-1-shaoqin.huang@intel.com

tools/testing/memblock/README

@@ -33,20 +33,23 @@ To run the tests, build the main target and run it:
 
 $ make && ./main
 
-A successful run produces no output. It is also possible to override different
-configuration parameters. For example, to include verbose output, specify the
-VERBOSE flag when building the main target:
+A successful run produces no output. It is possible to control the behavior
+by passing options from command line. For example, to include verbose output,
+append the `-v` options when you run the tests:
 
-$ make VERBOSE=1
+$ ./main -v
 
 This will print information about which functions are being tested and the
 number of test cases that passed.
 
-To simulate enabled NUMA, use:
+For the full list of options from command line, see `./main --help`.
+
+It is also possible to override different configuration parameters to change
+the test functions. For example, to simulate enabled NUMA, use:
 
 $ make NUMA=1
 
-For the full list of options, see `make help`.
+For the full list of build options, see `make help`.
 
 Project structure
 =================