os/bluestore/Allocator: drop unused return value in release function

src/os/bluestore/Allocator.h

@@ -43,7 +43,7 @@ class Allocator {
     return allocate(want_size, alloc_unit, want_size, hint, extents);
   }
 
-  virtual int release(
+  virtual void release(
     uint64_t offset, uint64_t length) = 0;
 
   virtual void dump() = 0;

src/os/bluestore/BitMapAllocator.cc

@@ -144,15 +144,14 @@ int64_t BitMapAllocator::allocate_dis(
   return num * m_block_size;
 }
 
-int BitMapAllocator::release(
+void BitMapAllocator::release(
   uint64_t offset, uint64_t length)
 {
   std::lock_guard<std::mutex> l(m_lock);
   dout(10) << __func__ << " 0x"
            << std::hex << offset << "~" << length << std::dec
            << dendl;
   insert_free(offset, length);
-  return 0;
 }
 
 uint64_t BitMapAllocator::get_free()

src/os/bluestore/BitMapAllocator.h

@@ -36,7 +36,7 @@ class BitMapAllocator : public Allocator {
     uint64_t want_size, uint64_t alloc_unit, uint64_t max_alloc_size,
     int64_t hint, mempool::bluestore_alloc::vector<AllocExtent> *extents) override;
 
-  int release(
+  void release(
     uint64_t offset, uint64_t length) override;
 
   uint64_t get_free() override;

src/os/bluestore/StupidAllocator.cc

@@ -239,15 +239,14 @@ int64_t StupidAllocator::allocate(
   return allocated_size;
 }
 
-int StupidAllocator::release(
+void StupidAllocator::release(
   uint64_t offset, uint64_t length)
 {
   std::lock_guard<std::mutex> l(lock);
   dout(10) << __func__ << " 0x" << std::hex << offset << "~" << length
 	   << std::dec << dendl;
   _insert_free(offset, length);
   num_free += length;
-  return 0;
 }
 
 uint64_t StupidAllocator::get_free()

src/os/bluestore/StupidAllocator.h

@@ -39,7 +39,7 @@ class StupidAllocator : public Allocator {
     uint64_t want_size, uint64_t alloc_unit, int64_t hint,
     uint64_t *offset, uint32_t *length);
 
-  int release(
+  void release(
     uint64_t offset, uint64_t length) override;
 
   uint64_t get_free() override;