[BouffaloLab] Add factory string data terminator (project-chip#29928)

* [BouffaloLab] Add factory string data terminator

* Restyled by clang-format

---------

Co-authored-by: Restyled.io <commits@restyled.io>

Author: shchen-Lab

src/platform/bouffalolab/common/FactoryDataProvider.cpp

@@ -406,6 +406,7 @@ CHIP_ERROR FactoryDataProvider::GetVendorName(char * buf, size_t bufSize)
     len = mfd_getVendorName(buf, bufSize);
     if (len > 0)
     {
+        buf[len] = 0;
         return CHIP_NO_ERROR;
     }
     else if (0 == len)
@@ -452,6 +453,7 @@ CHIP_ERROR FactoryDataProvider::GetProductName(char * buf, size_t bufSize)
     len = mfd_getProductName(buf, bufSize);
     if (len > 0)
     {
+        buf[len] = 0;
         return CHIP_NO_ERROR;
     }
     else if (0 == len)
@@ -498,6 +500,7 @@ CHIP_ERROR FactoryDataProvider::GetPartNumber(char * buf, size_t bufSize)
     len = mfd_getPartNumber(buf, bufSize);
     if (len > 0)
     {
+        buf[len] = 0;
         return CHIP_NO_ERROR;
     }
     else if (0 == len)
@@ -519,6 +522,7 @@ CHIP_ERROR FactoryDataProvider::GetProductURL(char * buf, size_t bufSize)
     len = mfd_getProductUrl(buf, bufSize);
     if (len > 0)
     {
+        buf[len] = 0;
         return CHIP_NO_ERROR;
     }
     else if (0 == len)
@@ -540,6 +544,7 @@ CHIP_ERROR FactoryDataProvider::GetProductLabel(char * buf, size_t bufSize)
     len = mfd_getProductLabel(buf, bufSize);
     if (len > 0)
     {
+        buf[len] = 0;
         return CHIP_NO_ERROR;
     }
     else if (0 == len)
@@ -561,6 +566,7 @@ CHIP_ERROR FactoryDataProvider::GetSerialNumber(char * buf, size_t bufSize)
     len = mfd_getSerialNumber(buf, bufSize);
     if (len > 0)
     {
+        buf[len] = 0;
         return CHIP_NO_ERROR;
     }
     else if (0 == len)
@@ -637,10 +643,10 @@ CHIP_ERROR FactoryDataProvider::GetHardwareVersionString(char * buf, size_t bufS
 {
 #if CONFIG_BOUFFALOLAB_FACTORY_DATA_ENABLE
     int len = 0;
-
-    len = mfd_getHardwareVersionString(buf, bufSize);
+    len     = mfd_getHardwareVersionString(buf, bufSize);
     if (len > 0)
     {
+        buf[len] = 0;
         return CHIP_NO_ERROR;
     }
     else if (0 == len)