Rearranged compile-time constant checks to live near lfs_init

lfs_init handles the checks/asserts of most configuration, moving these
checks near lfs_init attempts to keep all of these checks nearby each
other.

Also updated the comments to avoid somtimes-ambiguous range notation.

And removed negative bounds checks. Negative bounds should be obviously
incorrect, and 0 is _technically_ not illegal for any define (though
admittedly unlikely to be correct).

lfs.c

@@ -8,23 +8,6 @@
 #include "lfs.h"
 #include "lfs_util.h"
 
-// Configuration Sanity Check
-#if (LFS_NAME_MAX <= 0) || (LFS_NAME_MAX > 1022)
-#error "LFS_NAME_MAX must be in the range (0, 1022]"
-#endif
-
-#if (LFS_FILE_MAX <= 0) || (LFS_FILE_MAX > 4294967295)
-#error "LFS_FILE_MAX must be in the range (0, 4294967295]"
-#endif
-
-#if (LFS_FILE_MAX > 2147483647)
-#warning "LFS_FILE_MAX>2147483647; lfs_file_seek, lfs_file_size, and lfs_file_tell will not function properly."
-#endif
-
-#if (LFS_ATTR_MAX < 0) || (LFS_ATTR_MAX > 1022)
-#error "LFS_ATTR_MAX must be in the range [0, 1022]"
-#endif
-
 
 // some constants used throughout the code
 #define LFS_BLOCK_NULL ((lfs_block_t)-1)
@@ -4123,6 +4106,21 @@ static int lfs_rawremoveattr(lfs_t *lfs, const char *path, uint8_t type) {
 
 
 /// Filesystem operations ///
+
+// compile time checks, see lfs.h for why these limits exist
+#if LFS_NAME_MAX > 1022
+#error "Invalid LFS_NAME_MAX, must be <= 1022"
+#endif
+
+#if LFS_FILE_MAX > 4294967295
+#error "Invalid LFS_FILE_MAX, must be <= 4294967295"
+#endif
+
+#if LFS_ATTR_MAX > 1022
+#error "Invalid LFS_ATTR_MAX, must be <= 1022"
+#endif
+
+// common filesystem initialization
 static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     lfs->cfg = cfg;
     lfs->block_count = cfg->block_count;  // May be 0