MINOR: shctx: Change max. object size type to unsigned int.

This change is there to prevent implicit conversions when comparing
shctx maximum object sizes with other unsigned values.
diff --git a/include/proto/shctx.h b/include/proto/shctx.h
index 594a81d..9fc6fad 100644
--- a/include/proto/shctx.h
+++ b/include/proto/shctx.h
@@ -32,7 +32,8 @@
 #endif
 
 int shctx_init(struct shared_context **orig_shctx,
-               int maxblocks, int blocksize, int maxobjsz, int extra, int shared);
+               int maxblocks, int blocksize, unsigned int maxobjsz,
+               int extra, int shared);
 struct shared_block *shctx_row_reserve_hot(struct shared_context *shctx,
                                            struct shared_block *last, int data_len);
 void shctx_row_inc_hot(struct shared_context *shctx, struct shared_block *first);
diff --git a/include/types/shctx.h b/include/types/shctx.h
index 53dca3f..7d9d8c8 100644
--- a/include/types/shctx.h
+++ b/include/types/shctx.h
@@ -40,7 +40,7 @@
 	struct list avail;  /* list for active and free blocks */
 	struct list hot;     /* list for locked blocks */
 	unsigned int nbav;  /* number of available blocks */
-	int max_obj_size;   /* maximum object size. */
+	unsigned int max_obj_size;   /* maximum object size (in bytes). */
 	void (*free_block)(struct shared_block *first, struct shared_block *block);
 	short int block_size;
 	unsigned char data[0];
diff --git a/src/shctx.c b/src/shctx.c
index 604fd7d..9fe12e8 100644
--- a/src/shctx.c
+++ b/src/shctx.c
@@ -292,7 +292,7 @@
  * and 0 if cache is already allocated.
  */
 int shctx_init(struct shared_context **orig_shctx, int maxblocks, int blocksize,
-               int maxobjsz, int extra, int shared)
+               unsigned int maxobjsz, int extra, int shared)
 {
 	int i;
 	struct shared_context *shctx;
@@ -359,7 +359,7 @@
 	LIST_INIT(&shctx->hot);
 
 	shctx->block_size = blocksize;
-	shctx->max_obj_size = maxobjsz;
+	shctx->max_obj_size = maxobjsz == (unsigned int)-1 ? 0 : maxobjsz;
 
 	/* init the free blocks after the shared context struct */
 	cur = (void *)shctx + sizeof(struct shared_context) + extra;