Revert "HAL_PX4: read from FRAM in 128 byte chunks"

This reverts commit a92366c455.

This commit may be associated with FRAM corruption on Pixhawk. Revert
until we understand why

libraries/AP_HAL_PX4/Storage.cpp

@@ -154,15 +154,8 @@ void PX4Storage::_storage_open(void)
 	if (fd == -1) {
             hal.scheduler->panic("Failed to open " MTD_PARAMS_FILE);
 	}
-        const uint16_t chunk_size = 128;
+	if (read(fd, _buffer, sizeof(_buffer)) != sizeof(_buffer)) {
-        for (uint16_t ofs=0; ofs<sizeof(_buffer); ofs += chunk_size) {
+            hal.scheduler->panic("Failed to read " MTD_PARAMS_FILE);
-            ssize_t ret = read(fd, &_buffer[ofs], chunk_size);
-            if (ret != chunk_size) {
-                ::printf("storage read of %u bytes at %u to %p failed - got %d errno=%d\n",
-                         (unsigned)sizeof(_buffer), (unsigned)ofs, &_buffer[ofs], (int)ret, (int)errno);
-                hal.scheduler->panic("Failed to read " MTD_PARAMS_FILE);
-            }
-            ofs += chunk_size;
 	}
 	close(fd);
 	_initialised = true;