Revert "rand() by default does increment of 1, randomizing more"

This reverts commit f7a6d25.

Author: Deepika

components/storage/blockdevice/COMPONENT_SPIF/TESTS/block_device/spif/main.cpp

@@ -49,9 +49,8 @@ void basic_erase_program_read_test(SPIFBlockDevice &block_device, bd_size_t bloc
     _mutex->lock();
 
     // Make sure block address per each test is unique
-    static unsigned block_seed = SPIF_TEST_NUM_OF_THREADS;
-    srand(block_seed);
-    block_seed += 2;
+    static unsigned block_seed = 1;
+    srand(block_seed++);
 
     // Find a random block
     bd_addr_t block = (rand() * block_size) % block_device.size();

features/storage/TESTS/blockdevice/general_block_device/main.cpp

@@ -189,9 +189,8 @@ void basic_erase_program_read_test(BlockDevice *block_device, bd_size_t block_si
     _mutex->lock();
 
     // Make sure block address per each test is unique
-    static unsigned block_seed = TEST_NUM_OF_THREADS;
-    srand(block_seed);
-    block_seed += 2;
+    static unsigned block_seed = 1;
+    srand(block_seed++);
 
     // Find a random block
     bd_addr_t block = (rand() * block_size) % (block_device->size());